Timing controller



Jan. 11, 1944. C.ISTANSBURY TIMING CONTROLLER Filed May 16, 1959 2SheetsSheet J.

III

I L [Ii I A I 1 Mww- Jan. 11, 1944.

v C. STANSBURY TIMING CONTROLLER Filed May 16, 1939 2 Sheets-Sheet 2PatentedJan. 11, 1944 UNITED STATES PATENT OFFICE TIMING oom'nonmaCarroll Stansbury, Wauwatosa, Wis assignor to Cutler-Hammer, Inc.,Milwaukee, Wis a corporation of Delaware Application May 16, 1939,Serial No. 273,957

10 Claims.

This invention relates to timing controllers, and while not limitedthereto is particularly applicable to resistance welding control systemsin which an impulse operated switch is used to control the period ofpower application in the weld? ing circuit,

' The invention has among its objects to providean improved impulseoperated switch for welding control systems of the aforesaid characterwhich is exceedingly quick acting and reliable in operation and which isadapted to provide exceedingly short and accurately controlled periodsof power application.

Another object is to provide an electromagnetically operated switch foruse in systems of the aforesaid-character having mechanical meansassociated therewith which is adjustable to provide selected periods ofcurrent flow in the resistance welding circuit upon energization of theswitch by a unidirectional current impulse of given value.

Another object is to providean electromagnetically operated switch ofthe double pole type having improved equalizing means associatedtherewith for insuring opening of the switch contacts simultaneously.

Various other objects and advantages of the .invention will hereinafterappear.

v The accompanying drawings illustrate an embodiment of theinventionwhich will now be described, it being understood that variousmothilcations may be made in the embodiment illustrated withoutdeparting from the spirit and scope of the appended claims.

1n the drawings,

-. A Figure 1 is a schematic view of a resistance welding control systemhaving a switch embodying the invention associated therewith;

Fig. 2 is a front elevational view of a mechanical embodiment of theswitch schematically shown in Fig. 1;

Fig. 3 is a side elevational view of the operating magnet shown in Fig.1, a. buffer device associated with the magnet being shown in section;

Fig. 4 is a sectional view on line 4-4 of Fig. l, the switch being shownin open position;

Fig. 5 is a sectional view on line 5-5 of Fig. 1 illustrating the switchin closed position, and

mounted upon opposite ends of a horizontally Fig. 6 is a plan view ofthe movable contact element shown in Fig. 1.

Referring to Fig. 1, the same schematically illustrates a two poleswitch embodying the invention, each pole including a stationary contactI and a cooperating movable contact}. The movable contacts 2 are carried.by a rotatable arranged equalizer lever 5 and are insulated therefrom,and said equalizer lever is pivotally mounted intermediate its ends upona rocker arm 1. Equalizer lever 5 is adapted to swing in a substantiallyhorizontal plane with respect to rocker arm I and said rocker armextends downwardly and rearwardly from said equalizer lever and ispivotally mounted intermediate its ends upon a pin 8 carried by a lever9 fixed to operating shaft 3. The lower end of rocker arm I is normallyheld in engagement with a stop projection It on lever 8 by a spring IIwhich engages the under side of lever 5. Spring H is adjustable by ascrew device l2 which is carried by a forwardly projecting lug IS onlever 9.

Operating magnet 4 includes a fixed magnet frame M, an operating windingi5 mounted upon said frame, and a movable armature member l6. Armaturemember I6 is adjustably secured to shaft 3 and is provided with a tailpiece H which extends downwardly from said shaft and cooperates with abuffer device iii of the character disclosed in the patent to ClarenceT. Evans et al., No. 2,134,179, dated Oct. 25, 1938.

Briefly described the buffer device I8 is provided with a headed pin 19having butt engagement with the tail piece l1 and connected to a piston20 movable ,within a closed housing 2|. Piston 20 is normally heldagainst the front end of housing 2| by a spring 22 and the pin I9associated with said piston acts as a stop to normally hold the movableswitch parts against the action of gravity in a position to provide arelatively narrow air gap between the movable contacts 2 and theircooperating stationary contacts I and also between armature member I5and magnet frame H. Upon energization of the magnet 4 to effect closureof the switch, tail piece I1 is entirely free to move away from the pinl9. Upon opening of the switch, tail pieceJl engages pin l9 and thebuffer device then acts to frictionaliy dissipate the kinetic energypresent in the moving switch parts and to bring the moving switch I 6towards its attracted position rocker arm I moves with respect to lever9 against the action forth the function and operation of theaforedescribed switch a simplified showing'of a timing controller of thecharacter disclosed in my aforementioned application is included inFig; 1. The switch is connected to supply current from a single phasealternating current supply circuit indicated by lines L -L to thewelding circuit (not shown) through the medium of a transformer T. The

timing control means shown includes a condenser 23, a pilot switch 24, arectifier and a gaseous electron tube .28 having a heated cathode 26, agrid 23 and an anode 28. Pilot switch 24 is provided with normallyclosed contacts 24" and normally open contacts 24 and the formercontacts serve to normally connect condenser 23 and rectifier 25 inseries across a single phase alternating current circuit indicated bylines Ii -L to eifect charging of said condenser. However, upon openingof contacts 24 and closure of contacts 24' of the pilot switch theoperating winding l5 of the switch is connected in series with condenser23 through the medium of 'tube 26 and said condenser then dischargesthrough said winding to effect response of the switch by a singleunidirectional current impulse. Grid 26 is controlled by means not shownin the drawings, but disclosed in my aforementioned .copendingapplication, to provide for discharge of condenser 23 through theoperating winding i5 01 the switch only at a definite point in the A. 0.cycle of the supp y circuit L -L?.

In accordance with the present invention condenser 23 is adjusted toprovide a unidirectional current impulse which is of sufficient value toeffect rapid movement of contacts 2intoengagement with their associatedstationary contacts I but insufilcient to effect acceleration of themoving switch parts after the contacts are brought into engagement. Uponarrest of the movable contacts in circuit closing position the movingswitch parts continue to move inwardly against the action of spring H,and said springis 50 adjusted that inward movement of said parts isarrested prior to sealing of armature member IS with the pole faces ofmagnet frame I4. Thus upon closure of the switch substantially theentire energy pres- I cut in the moving switch parts is stored in sprinH, and upon cessation of inward movement of said parts the same areaccelerated in circuit opening direction under the action of saidspring. It is thus apparent" that the speed at which the contacts 2 aremoved out of engagement with the stationary contacts I is substantiallythe same as the speed at which said movable contacts are moved intoengagement with said stationary contacts. In practice it has been foundthat when the switch is energized by a current impulse of a given valuethe interval during which the contacts remain in closed position issubstantially proportional to the degree of continued movement of themoving switch parts which occurs after the contacts are moved intoclosed position. Thus y varying the degree Of compression of spr I I thedegree of inward movement of the moving switch parts after the contactsare brought into engagement may be varied tovarythe periods of powerapplication in the welding circuit. In practice it has been found that aswitch constructed and operated as above described is adapted to provideexceedingly small and accurately controlled periods of powerapplicationcorresponding to as low as /2 cycle of the current in the supply mains L--L Referring now to Figs. 2 to 6, inclusive, the same illustrate amechanical embodiment of the switch schematically illustrated in Fig. 1.As shown ,in Fig. 2, the switch is mounted upon a vertical insulatingpanel 28, and each pole thereof has a blowout device 29 associatedtherewith of the construction disclosed in the copending application ofT. B. Jochem et al., Serial No. 217,194, filed July 2, 1938. Each of thestationary contacts l is fixed to' the front end of an arc horn 30associated with its respective blowout device (Fig. 4) and each of saidarc horns is mounted upon the front face of panel 28 and is connected toa terminal element 3| throughthe medium of a blowout coil 32.

The movable contacts 2 are fixed to brackets 33 which are mounted uponinsulated arms 34 of equalizer lever 5 and each of said contacts has aflexible lead 35 associated therewith which is connected to a terminalelement 36 mounted upon the front face of insulating panel 23. v Ashereinbefore stated, equalizer lever 5 is pivotally mounted intermediateits ends upon a rocker arm I. As shown in Fig. 5, said equalizer leveris provided with a forwardly extending projection 31 having an upwardlyextending spindle 38 formed on the upper side thereof which is rotatablysupported .within an opening in a bearing projection 39 formed on theupper end of rocker arm 1. The upper face of projection 31 on equalizerlever 5 is held in frictional engagement with the lower face of bearingprojection 39 by a screw 40 extending through an opening in spindle 38.As shown in Fig. 5 the upper end of screw 40 has a spring washer 4|associated therewith which is held under compression against the upperface of bearing projection 39 by a nut 42 on the upper end of saidscrew.

As hereinbefore stated, and as shown in Fig. 5, rocker arm 1 extendsdownwardly and rearwardly with respect to equalizer lever 5 and ispivotally mounted intermediate its ends upon a pin 8 carried by a lever9 fixed to operating shaft 3. Also as hereinbefore set forth, the lowerend of rocker arm I is normally held in engagement with a stopprojection ID on lever B by a spring I I which is adjustable by a screwdevice l2'carried by a forwardly projecting lug l3 on lever 9.

As shown in Fig. 5, the upper end of spring H is held within a recess inthe underside of projection 3'! on equalizer lever 5 and the screwdevice i 2 is associated with the lower end of said spring. Screw devicel2 includes an internally threaded bushing 43 which contains a screw 44having an enlarged head 45 on the upper end-thereof for engaging thelower end of spring I I. Bushing 43 is rotatably mounted within anopening in projection l3 on lever 9 and the lower end of said bushinghas an adjusting knob 46 fixed thereto, while the upper end thereof isprovided with an enlarged circular head 41 which engages the upper .faceof said projection. Head 41 of bushing 43 has teeth formed on theperiphery thereof and said bushing is releasably held against rotationby a spring pressed ball 48 which engages said teeth and is supportedwithin a drilled opening in the hub portion of lever 9. Screw 44 is heldagainst rotation by a pin 49 which is fixed to the head 45 of said screwand extends forwardly into a vertical slot 50 in a U-shaped gauge membermounted upon projection iii of lever 9.

Upon rotation of sleeve 43 by knob 46 the screw 44 i adjusted verticallyto vary the degree of compression of spring ll, As hereinbefore setforth, the period of power application in the welding circuitisdetermined by the degree of compression of spring ll. As is apparent,the position'of pin 49 within the slot 50 indicates the degree ofcompression of spring II and in practice the front face of gauge member5| is provided with markings 52 for indicating the periods of powerapplication which result from various settings of .said spring.

As shown in Fig. 2, theright end of shaft 3 is journaled upon a pin 53carried by a bracket 54 mounted upon the front face of insulating panelv 28 and the left end of said a pin 55 carried by a bracket 56associated with the magnet frame H of operating magnet 4. Bracket 56, asshown in Fig. 3, is securedto the front face of insulating panel 28 bybolts 51 and the same i provided with two forwardly extending arms 58and 59 which carry the pin 55.

Armature member 16 of magnet 4 is rotatably mounted upon pin 55 and isoperatively connected to shaft 3 through the medium of a down wardlyextending lever 60 which is fixed to said shaft. As shown in Fig.2, thelower end of lever 60 is provided with a horizontal extension 5i havinga vertical face 62 which is engaged by a bushing 63 mounted within anopening in the tail piece ll of armature member l6. Bushing 63 isclamped against the vertical face 62 of lever 65 by a screw 64 whichextends through the opening in said bushing and is threaded into theextension shaft is journaled upon 6| on said lever. The opposing facesof bushing 63 and extension 6| on lever Ell are formed to provideinterlocking teeth 65 and as is apparent said teeth provide a rigidcoupling between armature member l6 and said lever. The interlockingteeth 65 on bushing 63 and extension Bl extend in the direction shown inFig. 3, and as is apparent upon loosening screw 64 lever 60 may beadjusted with respect to bushing 63 to vary the angular position ofshaft 3' and its associated contacts 2 with respect to armature memberl6. Such adjustment provides for variation of both of the air gapsbetween movable contacts 2 and their associated stationary contacts Iand it should be noted that the equalizing mechanism associated withmovable contacts 2 renders it practical to employ a single means foreffecting adjustment of both of the air gaps.

As hereinbefore tated, the switch is provided with a buffer device I8which is associated with armature member l6 and acts to effect arrest ofthe moving switch parts in open position without rebound. As shown insaid buffer device is mounted upon the rear face of insulating panel 28and the headed pin 19 which cooperates with the tail piece ll ofarmature member l6 extends forwardly through an opening in said panel.

What I claim as new and desire to secure by Letters Patent is:

1. In a timing controller for an electric circuit, in combination, anormally open switch for controlling said circuit, an operating membertherefor, a spring operating connection between said member and saidswitch acting upon movement Fig. 3, the housing 2| of of said operatingmember in one direction out o! a given normal position to efiect closureof said switch, said spring operating connection permitting overtravelof said operating member upon closure of said witch, a power operateddevice responsive to move said operating member out-of normal position,and means for controlling said device to provide for movement of saidoperating member out of normal position under the action of. apredetermined power impulse to effect closure of said switch and to alsoeffect over-travel of said operating member after closure of said switchsolely by inertia against the action of said spring operating connectionto thereby provide for momentary closure of saidswitch.

2. In a timing controller for an electric circuit, in combination, anormally open switch for controlling said circuit, an operating membertherefor, a spring operating connection between said member and saidswitch acting upon movement of said operating member in one directionout of a given normal position to effect closure of said switch, saidspring operating connection permitting overtravel of said operatingmember upon thereby ing, member closure of said switch,electroresponsive means for moving said operating member out of normalposition, means for energizing said electroresponsive means by apredetermined power impulse to effect closure of said switch and to alsoeffect over-travel of said operating member after closure of said.switch solely by inertia against the action of said spring operatingconnection to maintain said switch in closed position for an intervalwhich is substantially proportional to the degree of over-travel of saidoperating member, and means for adjusting said spring operatingconnection to vary the degree of over-travel of said operating memberunder the action of said predetermined power impulse. 3. In a timingcontroller for an electric'circuit, in combination, a switch forcontrolling said circuit, said switch including a plurality of movablecontacts biased to open position and providing a plurality of gaps insaid circuit, an operating member for said switch, a single springoperating connection between said operating member and said movablecontacts acting upon movement of said operating member in one directionout of a given normal position to move said contacts into closedposition, said spring operating connection permitting over-travel ofsaid op-. erating member upon closure of said contacts, an

electroresponsive device for moving said operatout of normal position,means for operating said device by a predetermined current impulse toeffect movement of said contacts into closed position and to also effectover-travel of said operating member after-- closure of said contactssolely by inertia against the action of said spring operating connectionto thereby maintain said contacts in closed position for an intervalwhich is substantially proportiona1 to the degree of over-travel of saidoperating member, and means for adjusting said spring operating con- Inection to vary the degree of over-travel of said operating member forvariation of the interval during which said contacts are maintained inclosed position.

4. In a timing controller for an electric circuit, in combination, acontrol switch including a plurality of movable contacts biased to openposition and providing a plurality of gaps in said circuit, an operatingmagnet therefor including a stationary magnet frame and a cooperatingmovable armature member, a single spring operatto the degree of ingconnection betwecnsaid armature member and said movable contacts foreflecting closure I of the latter upon attraction or said armaturemember out or a given normal position, said spring operating connectionpermitting overtravel of said armature member upon closure of saidcontacts, and means for energizing said operating magnet by a currentimpulse which is of a given value to efiect closure of said contaow andto also eflect overtravel of said operating member upon closure of saidcontacts solely by inertia against the action or said spring totemporarily maintain said switch in closed position tor a period whichis substantially proportional overtravel of said armature member.

5. In a timing controller for an electric circuit, in combination, acontrol switch for said circuit including a plurality of movablecontacts biased to open position and providing a plurality of gaps insaid circuit, an operating magnet therefor including a stationary magnetframe and a cooperating movable armature member, a single springoperating connection between said armature member and said movablecontacts for ettecting closure 01' the latter upon attraction of saidarmature member out of a given normal position, said spring operatingconnection permitting overtravel or said armature member upon closure ofsaid contacts, means for energizing said operating magnet by a currentimpulse which is of a given ,value to effect closure of said contactsand to also efl'ect overtravel or said armature member upon closure ofsaid contacts solely by inertia against the action of said spring tomaintain said conta'cts in closed position for a period which issubstantially proportional to the degree of overtravel of said armaturemember, means for adjusting said spring to vary the degree of inertialovertravel of said armature member, and means associated with saidadjusting means for indicating periods or closure of said switchcorresponding to different settings of said Spring.

6. An electromagnetically operated control switch comprising a pair ofstationary contacts, movable contacts cooperating with said stationarycontacts and biased out of engagement there-. with, an equalizer levercarrying said movable contacts, said'equalizer lever being bodilymovable to eil'ect simultaneous operation of'said movable contacts andbeing pivotally'supported to permit self-alignment of said movablecontacts with respect to said stationary contacts, an operating magnetfor said movable contacts including a stationary operating winding and amovable armature member to be attracted out of a given normal positionby said winding, and a single spring operating connection between saidarmature member and said equalizer lever for moving said movablecontacts into circuit closing position upon attraction 01' said armaturemember out of normal position,

01' said movable said operating member s d spring oncrating connectionpermitting overtravel of said ,movable out 01' normal switch comprisingoperating member, upon said operating member and carrying said equalizerlever, a spring normally holding said am in a given angular positionwith respect to said operating member, an operating magnet including astationary operating winding and a movable armature member fixed to saidoperating member, said armature member being biased toward a givennormal position to maintain said movable contacts in open position andbeing movable out oinormal position by said winding to move said movablecontacts into closed position through the medium of said spring and saidarmature member being capable oi overtravel against the action or saidspring upon arrest of said movable contacts in closed position.

8. An electromagnetically operated control switch comprising a pair ofstationary contacts, movable contacts cooperating therewith, anequalizer lever carrying said movable contacts, said lever being bodilymovable to voperate said contacts simultaneously and being pivotallysupported intermediate said movable contacts to permit self-alignment ofthe latter with respect to said stationary contacts, a rotatableoperating member, an arm pivotally mounted upon izer lever, a springnormally holding said arm in a given angular position with respect tosaid operating member, an operating magnet including a stationaryoperatingwinding and a movable armature member fixed to said operatingmember, said armature member being biased toward a given normal positionto maintain said movable contacts in open position and being position bysaid winding to move said movable contacts into closed 9051-- tionthrough the medium or said springsaid armature member being also capableof overtravel against the action I said spring upon arrest 01 saidmovable con cts in closed position, and means for adjusting said springto vary the opposing action thereof upon overtravel of said armaturemember.

9. An electromagnetically operated control a pair of stationarycontacts, movable contacts cooperating therewith, an equalizer levercarrying said movable contacts, said lever being bodily movable tooperate said contacts simultaneously and ported intermediate said permitself-alignment of movable contacts to ing member, an arm pivotallymounted upon said operating member and carryi g said equalizer lever, aspring normally holding said arm in a given angular position withrespect to said operating member, an operating magnet including thereofupon overtravel oi. said armature member, and means for adjusting saidoperating meman arm pivotally mounted and carrying said equal-,

being pivotally sup-,

the latter with respect to said stationary contacts, a rotatableoperat-,

, able armature member to be attracted out or a given normal position bysaid winding. 9. single spring operating connection between saidarmature member and said equalizer lever for moving said movablecontacts into circuit closing position upon attraction of said armaturemember out of normal position, said spring operating connectlonpermitting overtravel of said armature member upon closure of saidmovable contacts, and means tor adjusting said equalizer-"lever withrespect to said armature member to provide for variation of the normalair gaps between said stationary and movable contacts.

CARROLL BTANBBURY.

